Astronomy timeline project

Lunar eclipse

2000 BCE

Lunar eclipse observed at Ur in Mesopotamia. The oldest known recording of a lunar eclipse took place at Ur more than 4000 years ago.

Chinese eclipses

1300 BCE

Chinese begin centuries long series of obs of eclipses. Chinese astronomers recorded 900 solar and 600 lunar eclipses over a period of 2600 years.

Dante

1300 BCE

Dante describes medieval picture of universe in "Divine Comedy". Dante's picture of the universe has the Earth at its center, surrounded by the spheres of the Moon, Sun, planets, the fixed stars, a crystalline sphere and, finally, paradise.

Works and Days

700 BCE

Hesiod describes practical uses for astronomy. Hesiod's poem The Works and Days contains practical astronomical advice for navigation and for agricultural activities.

Thales prediction

585 BCE

Thales said to have predicted solar eclipse. The eclipse took place during a battle between the Lydians and the Persians. They were so stunned by the eclipse they ended the battle

Very Old Earth

500 BCE

Xenophanes concludes that the Earth is very old. Xenophanes reasoned that stratified rocks were laid down as layers of sediments on the ocean floor. Given the thickness of the rocks, he concluded that the Earth is ancient.

Herodotus

450 BCE

Herodotus concludes Earth is at least thousands of years old. Herodotus reasoned that it would have taken millenia for the annual Nile flood to have produced the Nile delta.

Moon Shadow

350 BCE

Aristotle argues celestial bodies are spheres. Aristotle used a number of proofs that the Earth is a sphere, including the observation that its shadow on the Moon during lunar eclipses is always a circle.

Aristarchus

280 BCE

Aristarchus finds relative dimensions of solar system. Aristarchus concluded that the Earth was much smaller than the distances to the celestial bodies. He also invented a heliocentric (Sun-centered) model for the solar system.

Ulugh Beg

Sep 30, 1420

Ulugh Beg builds observatory at Samarkand. Beg also compiled a star catalog based on his own observations.

Columbus

Sep 30, 1504

Columbus uses lunar eclipse prediction to influence Arawaks. From his almanac, Columbus knew that a lunar eclipse would occur on February 29. He impressed the Arawaks with his accurate prediction that the Moon would rise "inflamed with wrath".

William Gilbert

Sep 30, 1600

William Gilbert proposes Earth has dipole magnetic field. Gilbert proposed that the Earth acts like a big magnet whose field aligns the small magnet used as a compass needle.